Beckman Coulter Multisizer 4, User Manual, Page: 63 / 238

PN A51387A
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Installing and Calibrating an Aperture Tube
Using Small Aperture Tubes (20 µm and 30 µm)
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Figure 3.5 Noise Profile, Contaminated System (20 µm aperture)
Using Appropriate Current and Gain Settings
The recommended current setting for 20 µm and 30 µm aperture tubes is 600 µA. Higher currents
can damage the aperture orifice and create noise as a result of the electrolyte overheating or
boiling.
Beckman Coulter recommends that you set the gain to 4 and the current to 600 µA.
You can set current and gain using the Change Aperture Tube Wizard (see Step 8: Set Current and
Gain , page 3-28 ) or the Edit the SOM window (see Standard Operating Method: Threshold, Current and
Gain , page 4-13 ).
Storing Small Aperture Tubes
To store an aperture tube:
1. Remove the aperture tube from the Sample Compartment.
2.
Rinse the tube (inside and outside) several times with pre-filtered, de-ionized water (see
Cleaning System Components and Accessories , page 3-6 ).
3.
Fill the ST Aperture Tube with pre-filtered, de-ionized water.
4. Fill a beaker with pre-filtered, de-ionized water.
5.
Place the Aperture Tube in a clean beaker filled with pre-filtered, de-ionized water.
6. Seal the top of the ST Aperture Tube with parafilm or plastic film.
7. Store in a dust-free environment.